Pneumatic-despatch-tube apparatus



J. G. MACLAREN. PNEUMATIC DESPATCH TUBE APPARATUS.

APPLICATION FILED AUG-25.1917- 132731 Patented Jan. 13,1920.

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J. G. MACLAREN. PNEUMATIC'DESPA-TCH TUBE APPARATUS.

APPLICATION FILED AUG.25, 1911- Ven iilys.

n \\1TH|1 .L. Iii... 8 M n j 6 2 9 2 E O a a MW w a a -2 .L w. I 6 M m 22 6 2 4 7 9 7, a e a a m e w 7 9 8 JAMES e. M CLAREN', or MAMABONECK, NEW YORK.

'PNEUMATIC-DESPATCH TUBE APPARATUS.

Specificationof Letters Patent.

Patented Jan. 13, 1920.

Application filed August 25, 1917. Serial No. 188,186.

To all whom it may concern:

Be it known that I, J AMES Gr. hIAoLAn-nN, a citizen of the United States, and a resident of Mamaroneck, \Vestchester county, New York, have invented an Improvement in Pneumatic-Despatch-Tube Apparatus, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to pneumatic carrier systems, being more especially concerned with pneumatic despatch tube apparatus of that class in which a single-transit tube is used for the transmission of carriers in opposite directions, and more particularly systems of the type in which an air pressure above that of the atmosphere is utilized for the propulsion of the carriers.

My invention will be best understood by reference to the following description, when taken in connection with the accompanying drawings of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is an elevation, partly in vertical section and partly broken away, of a pneumatic despatch tube apparatus embodying my invention;

Fig. 2 is a plan on an one of the terminals;

Fig. 3 is a sectional view on line 3-3 of Fig. 2, showing the parts in the relative positions which they normally occupy;

enlarged scale of Fig. 4 is a sectional view' similar to Fig. 3, but showing the parts in the positionwhich they occupy during the transmission of a carrier from the terminal there represented;

Fig. 5 is a detail, sectional view on line 5-5 of Fig. 4; and

Fig. 6 is a detail, sectional view on line 66 of Fig. 4E.

Referring to the drawings, andto the em bodiment of my invention which is illustrated therein, I have there shown a pneumatic despatch tube apparatus comprising a transit tube 11 connecting two terminals 12, which may be, and are hereii'i, identical in construction, though-one is arrai' iged for upward and the other downward discharge of carriers. Each of these terminals is herein equipped with a chute 1'3'of theusualcoa struction to check the speed of the emerging carrier, and. to assist in bringin 'the latter to rest at a suitable point. As a means for supplying an air current for the propulsion of the carriers through the transit tube, I have herein provided a motor-driven air compressor let, which delivers compressed air through a pipe 15 to a receiver or storage tank 16, whence branch pipes 17 lead to the respective terminals 12. Since the latter are herein of identical construction, a detailed description of one will suflice for both.

Referring now more particularly to Figs. 2 to 6, inclusive, the terminal 12 is provided with a chamber 18 communicating in any suitable manner with the transit tube 11', the latter for this purpose being herein provided with one or more perforations 19. Oommunication between the air supply pipe 17 and the transit tube 11 maybe controlled by any suitable valve, such for example as a valve 20 hereinafter called the air inlet valve, the latter cooperating with a suitable seat 21, and having a stem 22 mounted to slide vertically in a guide 23. Any suitable means may be provided for normally holding the valve 20 seated, but herein I have provided a helical spring 24 encircling the valve stem within the guide 23, and serving in an obvious manner to assist the air pressure in holding the valve seated except when it is purposely opened.

As a means for closing the carrier inlet and outlet of the transit tube, I have herein provided a suitable closure 25, sometimes called a door or gate, of common form, usually made of leather or some other suitable more or less yielding material, secured to a reinforcing plate 26 and carried by a lever 27. As a means for attaching the door to the lever, I have herein provided a bolt 28 passing through both, and encircling this bolt is a suitable spring 29, interposed between the plate 26 and the lever 27 and constantly tending to move the door 25 away from the lever 27 for purposes which will presently appear.

The door-carrying lever 27 is herein fulcr'umed on a pivotal pin 30, and is'interposed between a pair of ears 31. As a means for normally holding the door open and auto-' matically returning it to its open position after having been closed, I may provide any suitable means, such as a spring although in the case of a downward discharging terminal this spring may be omitted if desired, and gravity alone relied upon to open the door. Any suitable type'of spring may be employed for this purpose, but herein the latter is helically coiled about a rod 33, and is interposed between two abutments 34.- and 35, one of which is mounted in fixed position on said rod, while the other is mounted to slide for a purpose which will presently appear. Herein, the rod 33 is pivotally connected to the lever .27 by a pivotal pin 36, and extends loosely through a perforation 37in a plate 38, the latter constituting the top or cover plate of the terminal 12 and being secured above to chamber 18 by a plurality of screws 39; The abutment may be, andis herein, mounted to rock with relation to the top plate 38, and for this purpose is herein provided with a pair of V-shaped projections 40, resting in shallow grooves in the side of the plate, and acting as a fulcrum resembling that 01 a scale beam. It will be evident that when the lever 27 is swung about the axis of its pivot 30, the axis of the pivot 36 will describe an arc of a circle, and hence the rod 33 will be swung back and forth about the knife edge projections 40 as a fulcrum. Any suitable means may be provided for limiting the opening movement of the door 25, but herein the rod 33 is provided with an abutment i1 adapted to engage the upper side of the plate 38, as shown in Fig. 3.

' The inlet valve 20 is preferably under the control of the described mechanism for closing the transit tube. This control may be effected by other means, but in the present example, I have provided a plunger 42 mounted to slide vertically in an upper guide 13 and a lower guide 14, and suitably connected to the valve stem 22 as by means of a lever 45 pivoted at 16, and having a forked or bifurcated end 17 which embraces the plunger and is held against a shoulder or collar -18 on the latter by means of the spring'hereinbetore described. The lower end of the guide 44- may be provided with a vent port 19 for the free entrance and escape of air to and from the space beneath the plunger -12, thereby to permit freedom of action of the latter.

The, plunger 12 may be actuated by the closure mechanism in any suitable manner, but herein the lever 27 is provided with a plate 50, which, during the closing movement of the door 25 is adapted to engage the I means may be employed, but herein I have provided'a latch in the form of a lever 51 escape of air.

Heretofore in terminals of this class, much difficulty has been experienced owing to the great pressure required to effect the release of the door-latching means. By the use of thedevices which I shall now describe, however, I have been enabled to obviate these difliculties, and to provide a door-releasing means which can be operated by a pressure no greater than that required to propel a carrier. The system thus possesses the advantage of being capable of operation with low as well as high pressures. I have also provided a door-releasing means which operates independentlyof the air inlet valve.

To these ends, I may provide any suitable pneumatic means to lock the latch. In the present instance, I have provided air-pressure responsive means in the form of a dia phragm 5a, suitably connected with the levrr 51 as by means of a post 55 and a pivotal pin 56. In this example, I have provided a housing 57, having a pair of cars 58, to which the lever 51 is fulcrumed, and into which said lever extends. The weight of the diaphragm 54, the post 55, the pivot 56 and the lever 51, constantly tends to move said lever into its unlatching position. The action of gravity may be assisted by a suitable spring 59 interposed between the top of the post and the under side of the housing 57 This constant tendency to unlatch or rei lease the door is resisted by air pressure to which the diaphragm 54 is subjected consequent upon the closure of the door. In the form selected for illustration, this is accomplished by providing beneath the diaphragm 54 a chamber 60 communicating with the chamber 18 by means of a port 61. When the door 25 is closed and air pressure is admitted to the chamber 18 through the opening of the air inlet valve 20, compressed air passes through the port 61 into the chamber 60, thereby lifting the diaphragm 54 and moving the latching arm 53 into the positionshown in Fig. a, and locking the door 25 in its closed position. The door should remain closed long enough to insure the discharge of the carrier from the termi nal at the other end of the line, whereupon the'door 25 at theterminal where the carrier-was introducedshould be allowedto open-and the air inlet valve 20 should be allowed to close, thereby to restore the parts to their normal condition. Inthe present example, I have provided pressure-responsive, means subject to control by pressure which propels it, the confinement of the air will act through suitable devices to maintain the door in its closed position, and the inlet valve in its open position. This obstruction may be due to several causes, among them belng the presence of a bend in the transmission tube, or a riser in which a carrier is being propelled in an upward direction. Such conditions, requiring the utilization of an increased power for the propulsion of the carrier, naturally produce an increased pressure in the system above that which obtains when the carrier is traveling horizontally or in a downward direction. In'the present instance, the pressure responsive means referred to is combined with a timing means in such a way that the latter is, or may be, reset from time to time during the transmission of the carrier, so as to increase the time interval by the necessary amount to insure the delivery of the carrier before the door is allowed to open and the inlet valve to close.

In the present instance, the chamber 60 communicates through one or more, herein a pair of ports 62, with a chamber 63, the latter inturn having means of communication with the outer atmosphere by a plurality of ports 64 having a combined area greater than that of the port 61. As a means for placing the chamber 63 in communication with-the outer atmosphere through the ports 64:, I have herein provided a piston valve 65 working in a cylinder 66 and 00-.

operating with a suitable valve seat 67. The chamber 63 maybe, and is herein, formed in the cover-plate 38-, while the cylinder 66 and valve seat 67 are preferably formed as separate parts secured to the cover-plate by a plurality of screws. 68. This construction not only facilitates the manufacturing and initial assembling of the parts, but alsopermits themtobe readily dismounted for the purpose of inspecting and cleaning the piston valve. The latter may be seated by the action of gravity alone, if desired, butherein I have provided a suitable spring 69, constantly tendmg to urge the same toward ,its seat. One or more, herein a plurality of ports 70 in the piston portion of the valve .65 provide communication between the chamber 63 and that portion of the cylinder G G which above the piston, so that no air can be ftrapped in this space to interfere with the proper working of the valve.

.. 'The -venting valve 65 may be timed by any suitable means, but herein I have provided 'air pressure responsive means includ- ,ing' d aphragm '7 ha ing one e posed to the action of atmospheric pressure in a chamber 7 2 and the ;otherl toa variable pressure in a chamber 73, the latter communicating with the chamber 18 through a passage 74 (see Figs. 3 and 5), the upper portion of this passage is herein formed by a pipe 75 suitably shaped to prevent the entrance of dirt, water, and oil, into the passage 74, the upper end of said pipe to this end being formed with agoose-neck or downward bend 76. The efl'ective area of the passage 74 may be regulated by suitable means, such for example as a needle valve 77, cooperating with a valve seat 78 for a purpose which will presently appear. The chamber 7 3 may be placed in communication with the atmosphere through a passage 79 controlled bya valve. 80, the latter in turn being carried by a valve stein-81 controlled conjointly with the inlet valve. 20 and the door 25. To this end, the upper end of the valve stem 81 is herein adapted for cooperation with the lever 45, so that when the inlet valve 20 is opened asshown in Fig. 1, the venting valve 80 is held to its seat and the passage 79 is closed, but when the valve 20 is closed, the pressure of the lever 15 on the valve stem 81 is removed, and the venting valve 80 can'be opened by the air pressure within the chamber 78. The expulsion of the air from the chamber 73 may be effected by any suitable ;means, such for example as a spring 82 acting in opposition to the pressure in the chamber 73. lVhen, owing to the closing of-the door'25 and the opening of the air-supply valve 20, compressed air is admitted from thelcham ber 18 by way of the passage 7 4: tothe chamber 73, since the'venting port 79 is then closed by the valve 80, the air pressure builds up in the chamber 7 8 and acts against the diaphragm 71 in opposition to the comtoward the right (Figs. 3 and 4:);

This movement of the diaphragm may be communicated to the venting valve 65 by any suitable means, as for example aplunger 83 secured to the diaphragm and having a shoulder or collar 84 normally separated from, but adapted to engage, thebifurcated depending arm 85 of a lever 86, the latter being fulcrumed on a pivot 87 and adapted to 3 engage a depending stem 88 of the valve 7! supply valve 20, compressed air is admitted to the chamber '18, an air pressure is gradually built up in the chamber 7 3 at a speed determined by adjustment of the timing valve 77. As the pressure builds up, .the diaphragm 71 is forced toward the} right (Figs. 3 and .1), and the shoulder Stat-first moves idly, finally bringing up against-the lever 86, as shown in Fig. l. The" time cons ined in the operation to this point provides \Vhen, owing to the opening of the air for the continuance of the air flow for the transmission of the carrier. This time, as will presently appear, is not fixed or predetermined, but is variable and subject to control by pressure conditions in the system due to the presence of the carrier in transit. When, however, the shoulder 84 brings up against the lever 86, and the latter lifts the venting valve 65, air rushes out of the chamber 60 by way of the passages 62, chamber 63 and ports 64, faster than air is supplied to said chamber by way of the port 61. As a consequence, the diaphragm 54 descends under the combined influence of gravity and the spring 59, thus moving the latch 53 out of engagement with the plate 50, whereupon the cover 25 is free to be opened under the influence of the spring 32, and the valve 20 is free to be closed under the influence of the spring 24. The closing of the valve 20 acts through the valve stem 22 to lift the lever 45, thereby releasing the valve stem 81 and allowing the venting valve 80 to be opened by the pressure within the chamber 73, the expulsion of the air through the passage 79 being effected by movement of the diaphragm 71 under the influence of the spring 82. This results in the restoration of the venting valve 65 to its initial position, whereupon the apparatus is in readiness for the introduction of another carrier. The chambers 72 and 73 are herein formed within a casing comprising two parts 89 and 90, between which the margin of the diaphragm 71 is clamped by a plurality of screws 91. The casing part 89 is herein provided with a stem 92, constituting a guide for the plunger 82, which is hollow, and the guide and plunger are chambered to provide a working space for the spring 82. A vent port 93 provides for the free entrance and exit of air, and permits freedom of action of the diaphragm 71.

It has been stated that the period occupied by-the shoulder 84 in taking up the lost motion between it and the lever 86 is determined automatically by pressure conditions within the transit tube, due to the presence of a carrier. This may be accomplished in various ways, but in the present instance, I have provided pressure responsive means comprising a diaphragm 94 having one face exposed to atmospheric pressure, and the other face exposed to the pressure in the transit tube. To this end, the margin of the diaphragm herein clamped between upper and lower casing parts 95 and 96, provided respectively with chambers 97 and 98. The chamber 97 communicates with the atmosphere through one or more, herein a plurality of ports 99, while'the chamber 981 communicates with the transit tube 11 through a passage 100. When the transit tube is open and not in use, both faces of the diaphragm 94 are subjected to atmospheric pressure, but when upon the insertion of acarrier for transmission the door 25 is closed and the air inlet valve 20 is opened, compressed air is supplied through the passage 100 to the chamber 98, thus exerting a lifting effect on the diaphragm 94.

This may be utilized in various ways to effect the release of the latch 53. In the present instance, the diaphragm 94 is utilized to operate suitable instrumentalities to vent the chamber 73 to the atmosphere, so that even though the diaphragm 71 may have started to move toward the right (Figs. 3 and 4), yet when the chamber 73 is vented, the diaphragm is restored to its initial position and must begin its travel all over again. This may happen once or several times during the transmission of the carrier. In the present example, this venting of the chamber 73 is effected by the use of a valve 101 controlled by the diaphragm 94, andcooperating with a suitable seat 102 of a valve casing 103, the latter communicating with the chamber 73 by way of a pipe 104. The valve 101 may be controlled by the diaphragm 94 in any other suitable manner, but is herein provided with a stem 105, mounted to slide freely in an arm 106, the latter being secured to a plunger 107 carried by the diaphragm. This plunger may be provided with a suitable weight 108. A spring 109 encircling the valve stem 105 and interposed between the valve 101 and the arm 106 is normally held under considerable compression by the weight of the parts 106, 107, 94 and 108. When, however, compressed air is admitted to the chamber 98, the'diaphragm 94 is lifted and the arm 106 lifts the valve 101. By suitable adjustment of the weight 108, the valve 101 may be caused to open under the influence of the air pressure which has been building up in the chamber 7 3, and when the valve is thus opened, this pressure is vented to the atmosphere through the pipe 104 and valve casing 103, whereupon the diaphragm 71 returns to its starting position and commences its travel anew.

Thus, it is evident that when, owing to the increased resistance to the travel of the carrier due to a bend or a riser, the pressure in the despatch tube rises sufficiently to open the valve 101, the timing mechanism is reset, and it may be thus re-set once or several times during the transmission of the carrier.

The general operation is as follows: Assuming that the doors 25 at both terminals are open, and the air supply valves 20 are closed, the operator at one station inserts a carrier in the transit tube 11, and then closes the door 25. It is found unnecessary in practice to slam the door shut with great force, as in the operation of other systems of this general type. This feature alone is warms very desirable, since it produces quieter action and obviates danger of breakage to the closure mechanism. As the door closes, it acts through the plunger 42 and lever 45 to open the air inlet valve 20, thereby admitting compressed air to the terminal and establishing an air flow which propels the carrier toward its destination.

In the meantime, the air pressure, is C0111- municated to the diaphragm54, and the latter acts through the latch 53 to hold the door 25 in its closed position to prevent the escape of compressed air at the, terminal Where the carrier was introduced, and to lock the inlet valve at such terminal open. The establishment of the air pressure within the terminal is eilective to set the timing device into operation by the admission of compressed air past the timing valve 77 into the chamber 75. .The diaphragm 71 now being forced toward the right (Figs. 3 and 4) approaches the lever 86. If now, owing to the obstruction presented by the carrier, the pressure builds up to a certain predetermined point in the chamber 98, the venting valve 101 is allowed to open under the pressure of the air in the chamber 73, and the diaphragm 71 reconnnences its operation. When, however, the pressure in the despatch tube drops to a point where the pressure in the chamber 73 is no longer able to overcome the tendency to close the valve 101, the shoulder 84 will commence to move the lever 86 toward the right, thus acting through the venting valve to open the chamber 60 to the atmosphere, whereupon the air is exhausted from said chamber faster than it receives air from the. port 61. As a consequence, thev tion in readiness for they introduction of thev The carrieris transmitted in the opposite; direction by. a like 0 oration, It is carrier.

found inpractice that one istinct advanta e of the apparatus is that. the air-supply valve closes quickly, and thus avoids the objectionable noise which is produced by gradually closing'air-valves of terminals of this, class heretofore.

While I have herein shown and described one specific form or embodiment of my invention for illustrative purposes, and have disclosed and discussed in detail the construction and arrangement incidental to one specific application thereof, it is to be understood that the invention is limited neither to the mere details or relative. arrangement of parts, nor to its specific embodiment herein shown, but that extensive deviations from the illustrated form or em.- bodiment of the invention may be, made, Without departing from the principles thereof.

Having thus described my invention, what Iclaim and desire by Letters Patent to Secure is 1. A pneumatic carriersystem comprising, in combination, a transmission tube, an entrance gate for said tube, air current oreating means, timing means controlling said gate and pressureresponsive means subjectv to control by pressure conditions due to, a carrier in transit to control the operation of said timing means, whereby said gate may be maintained in carrier-transmitting position, irrespective of the time required for the transmission of the carrier.

A pneumatic carrier system comprising,;in combination, a transmission tube, an

entrance gate for said tube, air current or ating means, means for locking said gate in carrier-transmitting position upon the despatch of a carrier, timing means controlling said locking means, and pressure-responsive means subject to control by pres sure conditions due to said carrier when in transit to control the operation of said timing means whereby said locking means may be maintained in its locking posit-ion, irrespective of the time required for the transmission of the carrier.

A pneumatic carrier system; comprise ing, in combination, a transmission tube, an entrance gate for said tube, air currentv creating-means, locking means for said gate, pressure-responsive means to operate said locking means to lock said gatein-carr-iertransmitting position upon the despatch of a carrier, and other pressureresponsive means subject to control by pressure condi tions due to said carrier, when intransit. to control the operation of the first-mentioned pressure -responsive means whereby said gate may be maintained in carrier-transmitting position, irrespective of the time re"- quired for the transmission ofthe'carrier;

4. A pneumatic carrier system comprising, in combination, a transmissiontube, an entrance gate for said tube, air-current creating means, air-current controlling means, timing'means controlling said gate and said air current controlling means and pressureresponsive means subject to control by pres-i sure-conditions due to a carrier intransit to control the operation of said timing" means 'whereby said gate may be maintained in carrier-transmitting position, irrespective of the time required for the transmission of the ing, in combination, a transmission tube, an entrance gate for said tube, air current creating means, air-current controlling means, means for locking said gate and said con trolling means-in carrier-transmitting position upon the despatch of a carrier, timing means controlling said locking means, and pressure-responsive means subject to control by pressure conditions due to said carrier when in transit to, control the operation of said timing means whereby said locking means may be maintained in its looking position, irrespective of the time required for the transmission of the carrier.

(5. A pneumatic carrier system comprising, in combination, a transmission tube, an entrance gate "for said tube, air-current creating means, air-current controlling means, locking means for said gate and said controlling means, )ressure-responsive means to operate said loclring means to lock said gate and said controlling means in carrier-transmitting position upon the despatch of a carrier. and other pressure responsive means subject to control by pressure conditions due to said carrier When in transit to control the operation of said timing means whereby said locking means may be maintained in its locking position, irrespective of the time required for the transmission of the carrier.

7. A pneumatic carrier system comprising, in combination, a transmission tube, an entrance gate for said tube, air current creating means, a valve to control commun1cation between said tube and said means, means for locking said gate and said valve in carrier-transmitting position, timing means controlling said locking means, and pressure responsive means subject to control by pressure conditions due to a carrier in transit to control the operation of said timing means whereby said locking means may be main tained in its locking position.

8. A pneumatic carrier system, comprising, in combination, a transmission tube, means for supplying compressed air for the propulsion of carriers through said tube, a valve for controlling the admission of the compressed air to said tube, an entrance gate for said tube, means for locking said gate in its closed position and said valve in its open position, timing means controlling said locking means, and means subject to control by pressure conditions in said tube due to a carrier in transit to control the operation of said ti1ning means whereby said locking means may be maintained in its locking position.

9.v A pneumatic carrier system comprising, in combination, a transmission tube, an entrance gate for said tube, a r-current creating means, pressure-responsive means for locking said gate in carrler-transmitting position, a second pressure-responsive means for controlling the first mentioned pressureresponslve means, and a third pressure-responsive means sub ect to control by pressure conditions due to a carrier in transit entrance gate for said tube, air-pressure creating means, a valve to control the supply of compressed air to said tube, locking means for locking said gate closed and said valve open, air pressure-responsive means to operate said locking means to lock said gate and said valve, and air pressure responsive means subject to control by pressure conditions due to a carrier in transit to control the operation of the first-mentioned responsive means whereby said gate may be maintained closed and said valve open, irrespective of the time required for the transmission of the carrier.

11. A pneumatic carrier system comprising, in combination, a transmission tube, an entrance gate for said tube, air-current creating means, locking means for said gate, pressure-responsive means rendered operative by establishment of carrier-propelling air-pressure in said tube to cause said looking means to lock said gate in carrier-traine mitting position upon the despatch of a carrier, and other pressureresponsive means rendered effective by a continuance of such air pressure in said tube to prevent the firstmentioned pressure-responsive means from causing said locking means to unlock said gate during the transmission of the carrier by such air pressure.

12. A pneumatic carrier system comprising, in combination, a transmission tube, an entrance gate for said tube, air-current creating means, air-current controlling means, locking means for said gate and said aircurrent controlling means, pressure-responsive means rendered operative by establishment of carrier-propelling air-pressure in said tube to cause said locking means to lock said gate and said air-current controlling: means in carrier-transnntting position upon the despatch of a carrier, and other pressure-responsive means rendered effective by a continuance of such air-pressure in said tubeto prevent the first-mentioned pressureresponsive means from causing said locking means to unlock said gate and said air-current controlling means during the transmission of thecarrier by such air-pressure.

In testimony whereof I. have signed my name to this specification.

J AMES G. MACLAREN. 

